Oil pan of an internal combustion engine

ABSTRACT

An oil sump of a combustion engine, including an anti-surge plate fastened to the oil sump and extending parallel to the bottom of the oil sump and an oil pump strainer immersed in the reservoir of the oil sump below the anti-surge plate. The oil sump includes a mechanism to keep the oil pump strainer immersed in the oil, including a first mechanism belonging to the oil sump and a second mechanism belonging to the anti-surge plate, the first and second mechanisms forming a baffle for the flow of oil.

The present invention relates to the field of motor vehicle internal combustion engines.

More specifically, the invention relates to an oil pan of an internal combustion engine comprising means forming a baffle for the oil flow designed to keep an oil pump strainer immersed in the oil.

An internal combustion engine usually comprises in its lower portion, also called the bottom of the engine, a cylinder block and an oil pan. An oil pump, driven by a crankshaft, draws up the oil stored in the bottom of the oil pan in order to send it, through an oil pump strainer, to moving elements of the engine such as for example the crankshaft bearings, the connecting rods or the pistons. The oil then returns by gravity to the oil pan.

In operation, the engine generates vibrations which are propagated and can create unwanted noises in the engine. In order to attenuate the noise reverberated by the oil pan and stiffen the bottom of the engine, reinforcing the structure of the oil pan with stiffening ribs and/or adding a generally horizontal anti-surge plate mounted in the oil pan are known.

However, such an anti-surge plate does not stiffen the bottom of the engine and at the same time create an oil volume stabilization zone in order to reduce the effects that roll can have on surging.

An object of the invention is therefore to provide an oil pan in which the oil pump strainer is always immersed in order to prevent any surging.

With this object in mind, the invention provides an oil pan of an internal combustion engine comprising means designed to keep the oil pump strainer immersed in the oil, said means comprising a first means belonging to the oil pan and a second means belonging to the anti-surge plate, said means forming a baffle for the oil flow.

Such an oil pan advantageously has its side walls and its bottom stiffened, and at the same time allows the creation of an oil volume stabilization zone.

The baffle thus created keeps the fluid near the strainer in various positions of the vehicle, the oil pump strainer being advantageously kept immersed in the oil and thus preventing any risk of surging.

According to other features of the invention:

-   -   the means forming a baffle for the oil flow can surround the oil         pump strainer, the means belonging to the anti-surge plate and         the means belonging to the oil pan being able to fit one inside         the other;     -   the lower ends of the means belonging to the anti-surge plate         and the lower ends of the oil pump strainer can have a gap         between them and the bottom of the oil pan;     -   the means belonging to the anti-surge plate and the oil pump         strainer can have generally the same height;     -   the means belonging to the oil pan can comprise an opening at         the bottom of the oil pan;     -   the means designed to keep the oil pump strainer immersed can be         of generally cylindrical shape and of different diameters;     -   the means belonging to the oil pan can be a cylinder         incorporated in the oil pan, and the means belonging to the         anti-surge plate can be a cylinder incorporated in the         anti-surge plate; and     -   the means belonging to the oil pan can be a cylinder attached to         the oil pan, and the means belonging to the anti-surge plate can         be a cylinder attached to the anti-surge plate.

The invention also relates to an internal combustion engine comprising an oil pan comprising such an oil pan.

Other features and advantages of the invention will emerge clearly on reading the following description of the non-limiting embodiment of the invention, with reference to the attached drawings, in which:

FIG. 1 illustrates a cross section of the oil pan according to the invention. In the remainder of the description, a longitudinal, vertical and transverse orientation will be adopted in a non-limiting manner, according to the L, V, T axis symbol referring to the orientation of the engine.

According to FIG. 1, only the elements of the engine required for the understanding of the invention have been drawn.

The oil pan 1, as illustrated in FIG. 1, is made in the shape of a reservoir or tray comprising a bottom which can be slightly inclined. The oil pan 1 comprises a bottom 21 and side walls. The side walls comprise two longitudinal side walls 220 and two transverse side walls 221.

The oil pan 1 is intended to contain the oil required for the lubrication of the moving elements of the engine. This oil is pumped from the oil pan 1 through the oil pump strainer 3, itself connected to an oil pump not illustrated in FIG. 1. The oil used then drains under gravity from the moving or stationary elements of the engine to the oil pan 1 in which it is collected.

The oil pan 1 comprises an anti-surge plate 2. The anti-surge plate 2 is mounted in the oil pan 1 for example on one of the longitudinal side walls 220, and extends parallel to the bottom 21 of the oil pan 1 generally as far as the side walls of the oil pan 1. Thus, once installed in the vehicle, the bottom of the oil pan 1 is parallel to the ground and the anti-surge plate 2 is parallel to the bottom of the oil pan 1 and the ground.

The anti-surge plate 2 thus divides the oil pan 1 into a chamber 23 lying between the upper edge of the walls 22 of the oil pan 1 and the anti-surge plate 2 on the one hand, and a reservoir 24 constituting the lower portion of the oil pan 1 in the shape of a tray.

The anti-surge plate 2 prevents on the one hand the oil contained in the oil pan 1 from coming in contact with moving elements such as for example the crankshaft, reduces the movement of the oil surface in the oil pan and therefore reduces surging and emulsification, and stiffens the walls of the oil pan 1.

The anti-surge plate 2 comprises a cavity 25 allowing an oil pump strainer 3 to go into the reservoir 24 of the oil pan 1.

The oil pan 1 comprises means 10, 20 forming a baffle for the oil flow which are designed to keep the oil pump strainer 3 always immersed in the oil, under the anti-surge plate 2, in the reservoir 24. The means 10, comprise a first means 10 and a second means 20 belonging to the oil pan 1 and the anti-surge plate 2 respectively.

These means 10, 20 forming a baffle for the oil flow are preferably of generally cylindrical shape. According to the embodiment in FIG. 1, a first cylinder 10 is incorporated in the oil pan 1, and a second cylinder 20 is incorporated in the anti-surge plate 2. It will be understood that this embodiment is given only as a non-limiting example, and that these cylinders 10, 20 can for example be elements attached to the oil pan 1 and the anti-surge plate 2 respectively. One of the means 10, 20 can be an incorporated element, while the other means can be an attached element.

The first cylinder 10 extends, in the vertical direction, from the bottom 21 of the oil pan 1 to the anti-surge plate 2, and comprises for example openings 11 at the bottom 21 of the oil pan 1 on sections of the first cylinder 10. The openings 11 lie advantageously on the longitudinal axis of the vehicle so that the oil does not escape and remains in the baffle during cornering, acceleration or braking for example. The number of openings 11 can vary, the first cylinder 10 can comprise for example an opening 11 on a section which lies parallel to one of the two longitudinal side walls 220 on the longitudinal axis of the vehicle, and an opening 11 on the section which lies parallel to the other opposite longitudinal side wall 220.

The first cylinder 10 advantageously stiffens the bottom 21 of the oil pan.

The second cylinder 20 is incorporated in the anti-surge plate 2. It extends the cavity 25 of the anti-surge plate 2 continuously, and extends in the vertical direction, from the anti-surge plate 2 to the bottom 21 of the oil pan 1.

The first cylinder 10 and the second cylinder 20 are of generally different diameters so that the second cylinder 20 of the anti-surge plate 2 lies inside the first cylinder 10 of the oil pan 1. Thus, as illustrated in FIG. 1, the first cylinder 10 of the oil pan 1 and the second cylinder 20 of the anti-surge plate 2 surround the oil pump strainer 3.

The cylindrical shape of the means 10, 20 forming a baffle for the oil flow is given as a non-limiting example. Their shape can for example be rectangular, or a different shape. The means 20 of the anti-surge plate 2 only has to lie inside the means 10 of the oil pan 1 on the one hand and the oil pump strainer 3 only has to pass inside the means 20 belonging to the anti-surge plate 2 on the other hand. It will be understood that the means 20 of the anti-surge plate 2 can lie outside the means 10 of the oil pan 1, and that the oil pump strainer 3 can then pass inside the means 10 belonging to the oil pan 1.

The lower ends of the second cylinder 20 of the anti-surge plate and the lower ends of the oil pump strainer 3 have a gap between them and the bottom 21 of the oil pan 1. A minimum distance d must be maintained so as not to have any suction noise during the pumping of oil and thus prevent any contact with the oil pan 1. The second cylinder 20 of the anti-surge plate 2 and the oil pump strainer 3 extending to the bottom of the oil pan 1 preferably have generally the same height so that the volume of oil for use is as large as possible. However, this arrangement is not compulsory.

The oil volume moves during acceleration, braking, and left or right cornering. An oil volume called the “surface intersection volume” is determined, this being the oil volume described by the intersection of the oil surfaces during acceleration, braking, and left and right cornering. Such an oil pan allows the strainer to be located in this surface intersection zone, which has not always been easy or possible. By placing the strainer in this zone, surging can then be prevented or delayed.

Such an oil pan allows the baffle for the oil flow to keep the oil pump strainer 3 always immersed in order to prevent any surging. The fluid is advantageously kept near the oil pump strainer 3 in various positions of the vehicle.

Such a baffle for the oil flow advantageously reduces the unwanted noises coming from the bottom 21 of the oil pan, and at the same time allows the oil to arrive in the reservoir 24 of the oil pan 1 at a satisfactory rate without escaping during cornering for example.

Such an oil pan stiffens the bottom of the engine not only by means of the anti-surge plate 2 which reinforces its structure, but also by means of the means 10 incorporated in it.

Another advantage of the invention is also to stiffen the bottom of the engine to reduce the noise reverberating in the oil pan 1 and at the same time create an oil volume stabilization zone to reduce the effects of roll on surging. 

1-10. (canceled)
 11. An oil pan of an internal combustion engine comprising: an anti-surge plate mounted in the oil pan and extending parallel to the bottom of the oil pan; an oil pump strainer immersed in the reservoir of the oil pan under the anti-surge plate; and means for keeping the oil pump strainer immersed in the oil, comprising first means belonging to the oil pan and second means belonging to the anti-surge plate, the first and second means forming a baffle for the oil flow.
 12. The oil pan as claimed in claim 11, wherein the first and second means surround the oil pump strainer, the second means belonging to the anti-surge plate and the first means belonging to the oil pan, the first and second means being able to fit one inside the other.
 13. The oil pan as claimed in claim 11, wherein the lower ends of the second means belonging to the anti-surge plate and the lower ends of the oil pump strainer have a gap between them and the bottom of the oil pan.
 14. The oil pan as claimed in claim 11, wherein the second means belonging to the anti-surge plate and the oil pump strainer have generally a same height.
 15. The oil pan as claimed in claim 11, wherein the first means belonging to the oil pan comprises an opening at the bottom of the oil pan.
 16. The oil pan as claimed in claim 11, wherein the first and second means are of generally cylindrical shape and of different diameters.
 17. The oil pan as claimed in claim 11, wherein the first means belonging to the oil pan is a cylinder incorporated in the oil pan.
 18. The oil pan as claimed in claim 11, wherein the second means belonging to the anti-surge plate is a cylinder incorporated in the anti-surge plate.
 19. The oil pan as claimed in claim 11, wherein the first means belonging to the oil pan is a cylinder attached to the oil pan and the second means belonging to the anti-surge plate is a cylinder attached to the anti-surge plate.
 20. An internal combustion engine comprising: an oil pan comprising a device according to claim
 11. 